The overall goal of this research is to examine in a population based cohort of men and women, the Framingham Study, the biologic and behavioral factors associated with age-related bone loss from different skeletal sites. The primary objectives are to measure vertebral fracture incidence and changes in metacarpal cortical width in men and women between the year of 1967-1968, when spinal and hand radiographs were first obtained on cohort participants, and 1992-1993, when films will be repeated as part of this study. The second objective is to determine risk factors (measured near the time of the initial X-rays) for these vertebral fractures and these changes in metacarpal cortical width. Risk factors will include weight, age of menopause, estrogen use, physical activity (leisure and occupational), caffeine, smoking, and alcohol. In addition, the association between vertebral fractures/metacarpal cortical width on baseline X-rays and later hip fracture will be examined. The third objective is to measure shorter term changes in bone mineral density (BMD) of the hip and radius (assessed by single photon absorptiometry and dual energy X-ray absorptiometry) among very old men and women by comparing BMD obtained in 1,154 cohort members (1987-1989) with repeat BMD to be obtained as part of this study. Risk factors for this change in BMD will include weight, physical activity (leisure), caffeine, smoking, alcohol, thiazide diuretics, testosterone levels, dietary calcium, 25 hydroxy-vitamin D levels and thyroid hormone replacement and hormone levels. The subjects for this proposal will include all participants in examination 22 (1992-1993) of the Framingham Study. At the time of their usual visit to the Framingham Study, all consenting subjects will undergo a lateral spine X-ray, an X-ray of both hands, and bone densitometry of the hip and spine (using dual energy X-ray absorptiometry-SPA) and radius (using single photon absorptiometry-SPA). The proposal will utilize existing data collected for the Framingham Study regarding risk factors for osteoporosis, and will capitalize on X-rays of the spine and hands previously done on the cohort between 1967-1968, and absorptiometric measurements first performed on the cohort between 1988 and 1989. Critical measurement issues will be carefully addressed by the combined expertise of the investigative team which includes epidemiologists, experts in bone densitometry, and a skeletal radiologist.